HP ProLiant 3000 Video Streaming Technology - Page 4

1-Wire Composite ECG068/0798 WHITE PAPER (cont.) 4... Analog Video Analog Composite Video Analog video represents video information in frames consisting of fluctuating analog voltage values. In early analog video systems individual video signals- brightness, sync, and color- were all combined into one signal known as "composite" video. This composite signal can be transmitted over a single wire. Compared to other forms of video, composite analog video is lowest in quality. "Compositing" can result in color bleeding, low clarity and high generational loss when reproduced. Analog Component Video The low quality of 1-wire composite video gave way to higher quality "component" video where the signals are broken out into separate components. Two of the most popular component systems are the Y/C 2-wire system and the RGB 3-wire system. Y (Luminance) C (Chroma) 2-Wire Y/C Component Video R (Red) G (Green) B Blue) 3-Wire RGB Component Video The Y/C system separates the brightness or luminance (Y) information from the color, or chroma (C) information. This approach-called "S-Video"-is used in Hi-8 and Super VHS video cameras. The RGB system separates the signal into three components-Red, Green, and Blue- and is used in color CRT displays. Y (Luminance) U (Hue) V (Saturation) Another approach to component video is to use Luminance (Y), Hue (U), and Saturation (V) as the three components. Hue describes the color's shade or tone, and saturation the "purity" or "colorfulness" of the color. 3-Wire YUV This approach dates back to the Component Video introduction of color TV. For color TVs to be backward compatible and for black and white TVs to be able to receive color signals, the color and brightness components were separated. Thus black and white TVs could subtract out the chroma-hue and saturation-information of a color signal and color TVs could display only the luma information received from a black and white transmission. This enabled both types of TVs to peacefully coexist. In turns out that YUV signals can be transformed into RGB signals and vice-versa by using simple formulas.